Apparatus and method for the robotic repairing of an underground pipe junction

ABSTRACT

An apparatus and method for sealing an underground junction between a lateral service line and a main pipeline from the inside-out. One embodiment provides a substantially rigid patching apparatus which may be positioned and installed with a robotic device within a main pipeline. The patching apparatus has a flange shaped to fit the internal diameter of the main pipeline and a tubular stem or sleeve which penetrates into the lateral service line. The patching apparatus contains an interconnection substrate such as felt, sponge or other similar material. The interconnection substrate may be impregnated with a bonding agent which sealingly interconnects the patching apparatus to the main pipeline and lateral service line. The seal provided by the inverted-tee patch effectively eliminates most water intrusion or the influx of plant roots and other matter which can seriously damage or obstruct the main pipeline. A remote control robotic arm is used in conjunction with a support cage to apply the patch to the underground junction between the main pipeline and lateral service line from within the main pipeline.

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 09/196,607, having a filing date of Nov. 20, 1998now U.S. Pat. No. 5,971,032, the application being incorporated here inits entirety by reference.

FIELD OF THE INVENTION

This invention relates to an apparatus and method for remotely repairingexisting underground pipe junctions from the inside-out, as opposed todigging a trench and replacing or repairing the pipe from theoutside-in.

BACKGROUND OF THE INVENTION

Sewer lines, water lines and other types of buried pipelines can developleaks over time. These leaks are a result of decaying materials such asthe clay used in the construction of the pipeline, obstructions whichmay clog a line, chemical exposure or crushing due to overburdenpressure due to the inferior materials used in very old pipelines. Manyolder lines require repair to prevent exterior leaking and possibleground water contamination. Additionally, without proper repair groundwater can infiltrate into the broken sewer lines, thus causingsignificant increase in the volume of throughput and the expense ofchemicals and other materials used for treatment of the sewer water.

Repairing leaking sewer lines and other forms of fluid transmissionlines is very expensive due to the previous necessity of digging atrench from the surface to physically remove the pipe. The removal andreplacement of this pipe from the surface is time-consuming, expensiveand not practical in many old commercial and residential neighborhoodsdue to narrow alleyways, heavy traffic and the volume of pipe locatedbelow existing buildings or other obstructions.

Thus, "trenchless technology" was developed which utilizes machinery andmethods of repairing sewer pipe and other buried transmission lines fromthe inside-out. This process eliminates the need for digging expensivetrenches aboveground. In brief, the existing main pipeline is repairedby installing a plastic liner which is inserted into the existingpipeline. The plastic liner is then bonded to the internal surface ofthe existing pipeline by heating or other methods. The existing lateralservice lines which feed the main pipeline are then located by the useof a robotic device with an optical camera. Once identified, a hole isdrilled by the robot mechanism into the existing pipeline, thusproviding access into the lateral service line.

Unfortunately, the hole drilled into the existing lateral service linedoes not provide a satisfactory seal, thus permitting significantvolumes of groundwater, as well as plant roots, dirt and other foreignobjects to infiltrate the main pipeline at the junction point betweenthe lateral service line(s) and the main pipeline. Additionally,contaminants within the main pipeline can potentially leak and pollutethe adjacent groundwater. Thus, a need exists to provide a reliablepatching mechanism to seal the junction point between the lateralservice line and main pipeline which can be operated remotely and whichfunctions from within the small internal confines of the main pipeline.

Others have attempted to seal the junction between the main pipeline andlateral service line, but known approaches have considerabledisadvantages. U.S. Pat. No. 5,329,063 to Endoh exemplifies a techniquewhere a flexible tubular liner is inserted into a lateral line so thatthe entire lateral line receives a lining. Air or liquid pressure isneeded to insert the reversed flexible liner into the lateral. Once theliner is extended by the air pressure from the junction to the other endof the lateral pipe, access to that other end of the lateral line isrequired to cut away any excess liner. In this way, the entire lateralpipe is lined from one end to the other.

As those skilled in the art can appreciate, installing a flexible linerin a lateral service line is very time consuming and difficult. Theapparatus required for installation has many moving parts and is complexto operate. Additionally, access to the distal end of the lateral line(i.e., the end away from the main pipeline) is needed to cut away theexcess liner. The complex setup required makes sealing the junction ofthe main pipeline and lateral service line both time consuming andexpensive.

Further, the results achieved by the flexible liners are erratic becausethe lateral service line is not a controlled environment. For example,the lateral may contain debris which will obstruct the flexible liner sothat when the liner is hardened, the obstructions will permanentlyinterfere with the flow in the lateral line. Additionally, theenvironment in which the flexible liner must be installed into issubject to wide temperature swings which further encumbers achievingconsistent results. Therefore, there is a need for quickly andinexpensively sealing the junction between a main pipeline and lateralservice line with consistent results. This is especially needed insituations where it is difficult or impractical to obtain access to thedistal end of a lateral service line.

SUMMARY OF THE INVENTION

It is thus one object of the present invention to provide an apparatusand method for sealing the junction point between a lateral service lineand a main pipeline from the inside-out, i.e., using trenchlesstechnology. Thus, in one aspect of the present invention a patchingapparatus is provided which may be positioned and installed with arobotic device within a main pipeline. The patching apparatus in oneembodiment is comprised of a polyvinyl chloride (PVC) material, or thelike, having a flange which is shaped to fit the internal diameter ofthe main pipeline and an extending stem which penetrates into thelateral service line.

In another aspect of the present invention, the patching apparatusflange contains an interconnection substrate such as felt, sponge oranother similar material to provide a resilient, compressible materialsuitable for sealing the pipe junction. The interconnection substratemay be impregnated with a bonding agent such as a water activated epoxyor grout which sealingly interconnects the patch to the main pipelineand lateral service line. Alternatively, an adhesive, glue, or othertype of material may be applied to the interconnector substrate justprior to installation. To further provide sealing in another embodiment,an annular gasket may be positioned around the stem portion to promotesealing engagement between the stem and the internal surface of thelateral service line. The seal provided by the inverted-tee patcheffectively eliminates most water intrusion or the influx of plant rootsand other matter at the junction point which can seriously damage orobstruct the main pipeline.

It is yet another object of the invention to provide a remotelycontrolled robotic arm capable of applying the inverted-tee patch to thejunction between the main pipeline and lateral service line from withinthe main pipeline. The robotic arm includes a support cage which holdsthe inverted-tee patch in place during insertion. The robotic armlaterally extends to apply the patch to the junction. Thus, in yetanother aspect of the present invention a robotic arm is interconnectedto a substantially elongated robot capable of traveling within a mainsewer or other transmission line. The elongated robot is generallypositioned by means of a remotely controlled assembly with an opticalcamera mechanism which properly identifies the junction point of themain pipeline and lateral service line.

It is yet another object of the present invention to provide asubstantially rigid patch which does not require curing or theapplication of pressure to install the patch at the junction between thelateral service line and the main pipeline. Thus, the possibility oferror is reduced since the patch is preformed and as such is notsusceptible to deformation or failure as a result of non-controllableenvironmental factors such as debris in the pipeline, cold temperatures,etc. Furthermore, this type of patch does not require an entire serviceline to be lined, but only the junction point. Thus, significant timeand expense can be saved while achieving a greater degree ofreliability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an robotic arm holding an inverted-tee patchimmediately prior to insertion into a lateral;

FIG. 2 is an end view of inverted-tee patch being installed into alateral;

FIG. 3 is a top view of a support cage which engages the inverted-teepatch;

FIG. 4 is an end view of the support cage of FIG. 3;

FIG. 5 is a side view of the support cage of FIG. 3;

FIG. 6 is a top view of an inverted-tee patch;

FIG. 7 is an end view of the inverted-tee patch of FIG. 6;

FIG. 8 is a side view of the inverted-tee patch of FIG. 6; and

FIG. 9 is an end view of the inverted-tee patch of FIG. 6 and furthershowing a sleeve in position to be slid over the stem of theinverted-tee patch to increase the external diameter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention generally relates to trenchless technology for therepair and reinforcement of pipes. More particularly, the presentinvention provides a method and an apparatus for installation of a patchto a junction between a lateral service line and a main pipeline.

Referring to FIGS. 1 and 2, a side and end view of the robot mechanism100 within a main pipeline 104 are respectively shown. The robotmechanism 100 includes an upper platform 108, an extension arm 112, asupport cage 116, scissor multipliers 120, a lower platform 124, and aslide (not shown). The robot mechanism 100 attaches to a power assembly(not shown) which remotely activates the scissor multipliers 120 androtates the robot mechanism 100.

The upper platform 108 at a forward end 130 is fixedly attached to theextension arm 112 which engages the support cage 116. The support cage116 is adapted to removably hold a patch 118 in place for insertion intoa lateral service pipe 126. The patch 118 in profile is shaped like aninverted-tee (see FIG. 8). Any overextension of the lateral service pipe126 beyond an inner surface of the main pipeline 104 is typically groundaway prior to insertion of the patch 118 so that the patch will mountflush within an inner surface of the pipeline 104, as further describedbelow. Each side of the robot mechanism 100 has a scissor multiplier 120which allows lateral extension. Two slots 128 on each end of the upperplatform 108 engage each scissor multiplier 120.

The lower platform 124 and attached slide is typically positioned nearthe bottom of the pipeline and provides support for the scissormultiplier 120 and upper platform 108. A front end 134 of the lowerplatform 124 is attached to the slide which supports the front end whileallowing it to easily move back and forth within the pipeline 104. Arear end 138 of the lower platform 124 attaches to the power assemblywhich has a scissor motor (not shown) and a rotation motor (not shown).The scissor motor activates the scissor multiplier 120 to change theelevation of the upper platform 108 with respect to the lower platform124. The rotation motor rotates the robot mechanism 100 with respect tothe power assembly. By rotating the robot mechanism 100, lateral linesnot vertically aligned with the flow in the main pipeline 104 becomealigned with the support cage 116.

The scissor multiplier 120 contracts and expands to respectively raiseand lower the upper platform 108 with respect to the lower platform 124under the control of the scissor motor. It is once again noted, thereare two scissor multipliers 120 on opposite sides of the platforms 108,124 (see FIG. 2). Slots 128 on the upper platform 108 and a slot 142 onthe lower platform 124 engage the scissor multiplier 120. When thescissor multiplier 120 contracts and expands, pins 146 slide move withinthe slots 128, 142. As shown in FIG. 2, the patch is inserted into thelateral line 126 when the scissor multiplier 120 contracts from thepartially expanded position depicted in FIG. 1.

Referring to FIGS. 3 through 5, the support cage 116 which removablyholds the inverted-tee patch 118 is shown. The support cage includes acylindrical stem 300, a cross member 304, an oval support 308, top andbottom talons 312, 316, and first and second talons 320, 324. The stem300 mates with the extension arm 112 of the robot mechanism 100 forsupport. The cylindrical stem 300 is rigidly attached to a center of thecross member 304. Each end of the cross member 304 is rigidly attachedto the oval support 308. To properly contour to the shape of the patch118 and the inside of the pipeline 104, the oval support 308 when viewedfrom the end (see FIG. 4) is convex. The talons 312, 316, 320, 324 areconnected on one end to the oval support 308 and shaped to removablymate with the inverted-tee patch 118. In this embodiment, only gravitykeeps the patch 118 attached to the support cage 116, but other methodscould also be used.

With reference to FIGS. 6 through 8, the inverted-tee shaped patch 118is illustrated. Included in the patch 118 is a tubular stem 600, aconvex flange 604, and an interconnection substrate 608 (shown in FIG.1). In a preferred embodiment the substrate may be impregnated with anepoxy, resin, glue or other type of attachment mechanism. The tubularstem 600 mates to a circular cutout 620 in the flange. To avoid matterpassing through the pipeline 104 from snagging on the flange 604, theedge of the stem is preferably beveled 616 toward the pipeline 104. Thepatch 118 is designed to seal the junction 122 between the main pipeline104 and lateral service line 126. When the patch 118 of this embodimentis properly installed, the tubular stem 600 is mated inside the lateralline 126, the convex flange 604 is coextensive with an inner surface ofthe main pipeline 104, and the impregnated interconnection substrate 608affixes the patch 118 to the junction 122. The patch 118 preventscross-contamination between the material outside the pipes and thematerial inside the pipes. Preferably, the flange 604 is formed to fitthe inner circumference of the main pipeline 104 and occupies a portionof the circumference equal to or greater than one and one-half times adiameter of the lateral line 126, although various shapes and sizes ofthe flange may be used as appreciated by one skilled in the art.

The interconnection substrate 608 (See FIG. 1) affixes the patch 118 tothe pipe junction 122. To absorb epoxy or grout, the interconnectionsubstrate 608 made of sponge, felt or the like, and is attached to abonding surface 612 of the flange 604. Having the interconnectionsubstrate 608 be absorbent allows easy transport of the epoxy whichmight otherwise drip off the flange 604. Additionally, theinterconnection substrate 608 provides an additional barrier to preventleakage at the junction 122. As can be appreciated by one skilled in theart, the junction 122 may have imperfections which would prevent epoxyalone from effectively sealing, but the deformable interconnectionsubstrate 608 conforms to any imperfections to provide a better seal.The interconnection substrate is preferably able to compress to aboutone-third or less of its original thickness during installation.Preferably, the interconnection substrate 608 is a sponge material of athickness greater than 5 mm which is impregnated with a liquid epoxy. Inother embodiments, the impregnated interconnection substrate 608 can beanything which bonds the patch 188 to the junction 122 and substantiallyprevents foreign matter, including water, from seeping into the pipes104, 126. In another embodiment, the interconnection substrate 608 isused in conjunction with an annular gasket on the stem 600 to provideimproved sealing between the stem and the lateral service line 126 tohelp prevent seepage into the main pipeline 104.

In an alternative embodiment of the present invention shown in FIG. 9, asleeve or bushing 690 may be provided to selectively increase thediameter of the stem 600 and provide an improved seal with the lateralservice line 126. More specifically, due to various intolerances of claypipe and other pipe materials the exact internal diameter of the lateralservice line 126 may vary. Therefore, to improve the seal between thelateral service line 126 internal diameter and the external diameter ofthe stem, a sleeve or bushing 690 may be positioned over the stem toincrease its diameter. The bushing 690 may be made of a durable plasticor fiberglass, or alternatively plastic, felt, rubber or other similarmaterials commonly known in the plumbing and pipeline industries.Although the bushing 690 may have a length less than the total length ofthe stem, it is feasible that the bushing 690 have a length shorter thanthe total length of the stem and still be effective.

The following discusses a method of using the aforementioned robotmechanism 100, support cage 116 and patch 118 to perform a patchingoperation. The first step requires identifying the lateral service line126 requiring a patch 113 after the installation of a liner in the mainpipeline 104. Identification may be done visually by an operator orremotely using a video camera or other sensing device. Once the lateralservice line 126 is identified, access is provided to the lateralservice line 126 by drilling a hole through the liner with the use of aremotely controlled drill attached to a robotic apparatus which ispulled through the main pipeline 104. If the lateral line 126overextends into the main pipeline 104, the excess can be trimmed with arobotic grinder or the like.

The patch 118 is typically prepared for attachment and placed on thesupport cage 116 before inserting the robot mechanism 100 into the mainpipeline 104. This preparation may require attaching the interconnectionsubstrate 608 to the bonding surface 612, at an earlier time, andapplying the epoxy or grout to the interconnection substrate immediatelyprior to use. Alternatively, the substrate 608 may be pre-attached tothe exterior surface of the flange and in a preferred embodiment, may bepre-impregnated with a glue or epoxy. The epoxy or grout typically has aviscus consistency for a period of time before hardening upon exposureto a catalyst. The catalyst for the hardening process may be air, heat,water, or any other suitable technique known in the art. Placing thepatch 118 on the support cage 116 is typically performed before therobot mechanism 100 is inserted into the pipeline 104 because afterinsertion there may not be sufficient clearance between the pipelinewall and support cage 116.

In the next step, the support cage 116 holding the inverted-tee patch118 is positioned so that when the support cage 116 is laterallyextended, the patch 118 will mate with the lateral service line 126.This may require dragging the robot mechanism 100 and attached powerassembly so that the patch 118 is longitudinally aligned in the mainpipeline 104 with the lateral service line 126. Often, the lateralservice line 126 is not aligned vertically with respect to the flow inthe main pipeline 104. Under these circumstances, the power assemblyactivates its rotation motor to angularly align the patch 118 with thejunction 122.

Once the patch 118 is properly positioned, the power assembly activatesthe scissor motor to contract the scissor multiplier 120. Thecontraction of the scissor pushes the support cage 116 and patch 118toward the lateral line 126. In this way, the tubular stem 600 isinserted inside the lateral line 126 and the convex flange 604 isaligned with the inside of the main pipeline 104. The patch 118 is heldin place with sufficient force until the epoxy or grout cures. Pressureis provided to the support cage 116 so that the interconnection material608 is compressed to sufficiently fill-in any imperfections in thejunction with interconnection substrate 608. In one embodiment, curingtakes approximately 25 minutes. After curing, the epoxy or grout appliedto the interconnection substrate 608 optimumly produces a water-tightseal between the lateral service line 126 and main pipeline 104 andholds the patch 118 rigidly in place.

After the scissor multiplier 120 is expanded to move the support cage116 away from the patch 118 affixed to the junction 122, the robotmechanism 100 and power assembly are free to be removed from thepipeline 104. In this way, a patch 118 may be used to seal the pipejunction 122.

While various embodiments of the present invention have been describedin detail, it is apparent that modifications and adaptations of thoseembodiments will occur to those skilled in the art. However, it is to beexpressly understood that such modifications and adaptations are withinthe spirit and scope of the present invention.

What is claimed is:
 1. A patch adapted for removable interconnection toa remotely controlled robot for insertion into a main pipeline tosealingly repair a junction between a main pipeline and a lateralservice line, comprising:a substantially rigid tubular stem having afirst end and a second end, the second end having a substantially openaperture for communication with the lateral service line; a convexflange having an exterior surface, an interior surface and a cutoutportion operatively sized and interconnected to the first end of saidtubular stem, wherein said tubular stem extends away from the exteriorsurface of said convex flange; and sealing means interconnected to theexterior surface of said convex flange having resilient deformationproperties adapted to provide sealing engagement between said convexflange and an interior surface of the main pipeline.
 2. The patch ofclaim 1, wherein said convex flange is substantially rigid.
 3. The patchof claim 1, wherein the exterior surface of said convex flange iscontoured to have a shape substantially coextensive with the interiorsurface of the main pipeline.
 4. The patch of claim 1, wherein saidconvex flange covers a portion of a circumference of the main pipelineat least 1.5 times a diameter of the lateral service line.
 5. The patchof claim 1, wherein said tubular stem has a first length less than asecond length of the lateral service line.
 6. The patch of claim 1,wherein said tubular stem has a first length less than half a secondlength of the lateral service line.
 7. The patch of claim 1, whereinsaid tubular stem has a first length less than a diameter of the mainpipeline.
 8. The patch of claim 1, wherein substantially an entirelength of said tubular stem is comprised of a rigid material both beforeand after insertion of said tubular stem into the lateral service line.9. The patch of claim 1, wherein said sealing means substantiallysurrounds the cutout portion of said convex flange.
 10. The patch ofclaim 1, wherein said sealing means is comprised of foam rubber, felt,rubber, synthetic polymer, sponge, or cloth.
 11. The patch of claim 1,wherein said sealing means has an uncompressed thickness of at leastabout 5 mm.
 12. The patch of claim 1, wherein said sealing means has acompressed thickness of less than about one-third of an uncompressedthickness.
 13. The patch of claim 1, wherein said sealing means furthercomprises an annular gasket positioned on an exterior surface of saidtubular stem wherein a seal is provided between said tubular stem and aninterior surface of the lateral service line.
 14. The patch of claim 1,wherein said patch further comprises an adhesive means interconnected toor impregnated within said sealing means.
 15. The patch of claim 1,wherein said sealing means comprises a permeable substrate materialimpregnated with an adhesive material.
 16. The patch of claim 1, furthercomprising a sleeve having an internal diameter greater than an externaldiameter of said rigid tubular stem, wherein said sleeve may beslidingly positioned over said rigid tubular stem to increase theexternal diameter of said rigid tubular stem.
 17. A method for remotelyinstalling a patch to an underground junction between a main pipelineand a lateral service line, comprising the steps of:(a) providing apatch comprising:a tubular stem having a first end, a second end and afirst length, wherein the second end has a substantially open aperturefor communication with the lateral service line: a convex flange havingan exterior surface, an interior surface and a cutout portionoperatively sized and interconnected to the first end of said tubularstem wherein the second end of said tubular stem extends away from theexterior surface of said convex flange; and a sealing substrateinterconnected to the exterior surface of said convex flange havingresilient deformation properties adapted to provide sealing engagementbetween said convex flange and an interior surface of the main pipeline;(b) determining a location of the junction between the main pipeline andthe lateral service line; (c) removably attaching said patch to asupport cage; (d) positioning said support cage adjacent the location ofthe underground junction; (e) activating a lateral extender to move saidsupport cage from a first traveling position to a second engagementposition so that said patch is positioned with said tubular stem withinthe lateral service line and said sealing substrate is positionedagainst an internal surface of the main pipeline proximate to saidlateral service line; (f) curing said patch so that said patch becomesfixedly connected to the internal surface of the main pipeline whereinsaid patch substantially prevents infiltration of foreign matter intothe main pipeline at the underground junction; (g) deactivating thelateral extender to move said support cage from the second engagementposition to the first traveling position; and (h) removing said lateralextender and said support cage from the main pipeline.
 18. The methodfor installing a patch of claim 17, wherein said tubular stem has afirst length less than half a second length of the lateral service line.19. The method for installing a patch of claim 17, wherein substantiallyan entire length of said tubular stem is substantially rigid both beforeand after insertion into the lateral service line.
 20. The method forinstalling a patch of claim 17, wherein said patch further comprises anadhesive means interconnected to or impregnated within said sealingsubstrate for interconnecting said substrate to the interior surface ofthe main pipeline.